If the economy is ever going to improve, President Trump is just going to have to do it himself.

That, at least, seems to be Trump’s guiding principle as chief executive of the United States. Previous presidents used the office as a bully pulpit to talk about what should be done, in general macroeconomic terms. Trump, instead, is pursuing the ultimate in ultra-microeconomics; he acts like he wants to walk into the boardrooms of major corporations and tell them how they should be run, how many people they should hire and where. His method: Persuade executives to appease him personally and allow him to take credit for their job creation, in a kind of modern economic version of droit de seigneur. He praises the companies that help his interests and shames the ones whose executives express concerns about his erratic leadership or vague policies on free trade, health care or defense.

The result: All major U.S. corporations are now in the customer service business, and Trump is their main customer. But Trump’s apparent understanding of the president’s duties on economic policy — that he should micromanage every part of it personally — can’t end well for workers, employers or stockholders. It can’t even end well for Trump, who will find out soon that his technique is limited and that he’s more likely to burn out than to make any kind of dent.

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Workers have already seen their jobs used as bargaining chips between the Trump administration and their employers. Even as president-elect, Trump’s meddling in the affairs of large U.S. companies was unprecedented. Trump and his vice president, Mike Pence, personally negotiated with Carrier to give the company a $7 million tax break to keep jobs in the United States. When Japan’s SoftBank wanted to find a better U.S. regulatory reception for Sprint, which it owns, chief executive Masayoshi Son found a way to allow Trump to take credit for the company’s previously announced plan to create 5,000 jobs. Amazon, whose founder Jeff Bezos owns The Washington Post, recently announced plans to add 100,000 jobs over the next 18 months, which Trump’s team happily took credit for. To thank Linda Bean, a member of the board of Maine-based clothing retailer L.L. Bean who’d given money to support his election, Trump urged his 20.6 million Twitter followers to buy L.L. Bean products.

On the flip side, when Boeing’s chief executive mildly critiqued Trump’s trade plans, the president-elect let loose with a storm of Twitter attacks that soon had the errant executive trying to make up with Trump.

It’s all in pursuit of the greater glory of the Trump name. The president will say his intention is to save jobs that would otherwise be lost overseas. The truth won’t back that up: Corporations are complex institutions, and they have limited resources. A firm may save some jobs to support Trump’s boasting and join in the reflected glory, but it could then just as easily cut jobs in another division less likely to catch the eye of the White House.

The Carrier deal, for instance, which Trump bragged that he’d spent Thanksgiving trying to put together, doesn’t look quite so good out of the spotlight. Most of the $16 million the company promised Trump it would invest in its Indiana plant will go toward automating the factory — which means some of the jobs saved will eventually be eliminated anyway. And those jobs — a total of about 800 — cost $7 million in Indiana state tax credits to keep. If Trump pulled off the same kind of deal every month of his first term, he’d spend $336 million to save about 35,000 jobs. (A total of 11.3 million jobs were created during Barack Obama’s eight years in office.)

In reality, the U.S. economy is enormous: Our gross domestic product, the total sum of goods and services in the country, hovers around $17 trillion annually. One human cannot move that needle manually, particularly from the White House, which manufactures nothing but influence. Thousands of corporations and small businesses affect the economy. Trump has focused on five or six large companies that can give him headlines.

The personal involvement is not designed to actually fix the economy. It can’t. Mostly, it’s theater, Trump is slowly structuring U.S. business the way he has structured his real estate holdings: by personally placing his name in giant letters on each company. Taking credit for work that’s not strictly his is a Trump specialty; it’s at the core of his licensing business, in which companies pay him to slap his name on buildings, clothes and steaks produced by others.

So now, when any major company has a job-saving strategy, Trump wants to say it’s “because of me.

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The president’s pattern of hounding companies over decisions that could reflect badly on him follows the same hyper-personal theory of economics.

Take Boeing, which won a federal contract to build the next generation of the presidential plane, Air Force One, which will be able to fly the 8,000-plus miles from Washington to Hong Kong without stopping. An hour after the company’s chief executive was quoted in a news column opposing Trump’s proposed tariffs on international trade, Trump began bashing the firm, claiming that Boeing’s Air Force contract was worth $4 billion — far too much, in his estimate. (The contract has not actually cost $4 billion yet; the government budgeted $2.7 billion for it, though that figure could go up.) “Cancel order!” he demanded.

But in Trump’s world, a strident tweet is not only an attack. It is also a summons, an invitation to a negotiation where the target may attempt to atone for an error. Boeing chief executive Dennis Muilenburg immediately called Trump and then made a pilgrimage to his “winter White House, ” Mar-a-Lago, somewhat nervously praised the president-elect and promised to make the planes for less money. Marillyn Hewson, chief executive of Boeing competitor Lockheed Martin, another Trump Twitter target, also rushed to meet with Trump and soothe shareholders. The key is that they have to come to him, and only him.

Nuance and facts don’t always have a place in Trump’s view of the economy, either. He attacked Ford during the campaign last year for its plans to build a $1.6 billion factory in Mexico, then took credit this month for the company’s announcement that it would cancel those plans and invest $700 million in a plant in Michigan, creating 700 jobs. “We thought we had a really good plan . . . we thought the whole equation worked pretty well, but we got lost in the Twitter world,” said Joe Hinrichs , the Ford executive who oversees its business in the Americas. Trump blasted Ford rival General Motors for making Chevy Cruze sedans in Mexico and selling them north of the border, even though it sells the vast majority of its Mexican-made cars outside the United States. When Macy’s dropped Trump’s China-manufactured menswear line in 2015 because of the candidate’s derogatory comments about Mexican immigrants, Trump immediately called for a boycott of the retailer. He was silent, though, about news this month that the chain plans to close stores and cut thousands of jobs.

The fallout from Trump’s attacks, ultimately, may not last much longer than the glow of his boasts. His tweets have sometimes driven down stock prices, but rarely by more than a percentage point, and the shares recovered fast. On Boeing’s stock chart, his Dec. 6 comments barely show up. (In fact, the next day, the company’s stock rose, and it is now near a year-long high.) High-speed traders can profit from instant Trump-driven fluctuations, even small ones, but most companies don’t have to worry that the president will wipe out their market valuations.

Maybe Trump doesn’t know it yet, but even before he moved into the Oval Office on Friday, he had used up his entire economic toolbox of tweet, attack and wait. A promise that “I alone can fix it ” got him into the White House. The real economy isn’t anywhere near as simple as the campaign trail was.